STUDY ON THE 3.5-CELL DC-SC PHOTO-INJECTOR*

Abstract In order to get high quality electron beam for PKU-ERL-FEL project. A 3.5-cell DC-SC photo-injector was designed and optimized. The pierce gun and 3.5-cell superconducting Nb cavity are DC acceleration section and RF acceleration section, respectively. A tuner for the whole 3.5-cell superconducting cavity has been designed. The beam parameters of 3.5-cell DC-SC photo-injector are also presented in this paper. The disadvantage and problem of 1.5-cell DC-SC photo cathode injector which was for principle demonstration have been overcame in the design of 3.5-cell DC-SC photo cathode injector